Communication node and methods performed thereby

ABSTRACT

Embodiments herein relate to a method performed by a first communication node operating in a wireless communications network. The first communication node adjusts a value of a Contention Window, CW, from a first value to a second value, the second value being a higher value than the first value, wherein adjusting the value is based on: one or more feedback timers having expired at a time of performing a sensing procedure in the absence of: a) a received uplink, UL, grant from a second communication node, or b) a downlink feedback from the second communication node for an Autonomous Uplink, AUL, transmission from the first communication node. Following adjusting the value, the first communication node initiates a sensing procedure performed prior to a transmission of an UL burst to the second communication node, wherein the sensing procedure uses the adjusted value of the CW.

TECHNICAL FIELD

The embodiments herein relate to a first communication node and a methodperformed therein. In particular embodiments herein disclose handlingaccess to a wireless communication network, e.g. procedure for gainingaccess to a channel.

BACKGROUND

Communication devices within a wireless communications network may bewireless devices such as e.g., User Equipments (UEs), stations (STAs),mobile terminals, wireless terminals, terminals, and/or Mobile Stations(MS). Wireless devices are enabled to communicate wirelessly in acellular communications network or wireless communication network,sometimes also referred to as a cellular radio system, cellular system,or cellular network. The communication may be performed e.g., betweentwo wireless devices, between a wireless device and a regular telephone,and/or between a wireless device and a server via a Radio Access Network(RAN), and possibly one or more core networks, comprised within thewireless communications network. Wireless devices may further bereferred to as mobile telephones, cellular telephones, laptops, ortablets with wireless capability, just to mention some further examples.The wireless devices in the present context may be, for example,portable, pocket-storable, hand-held, computer-comprised, orvehicle-mounted mobile devices, enabled to communicate voice and/ordata, via the RAN, with another entity, such as another terminal or aserver.

Communication devices may also be network nodes, such as radio networknodes, e.g., Transmission Points (TP). The wireless communicationsnetwork covers a geographical area which may be divided into cell areas,each cell area being served by a network node such as a Base Station(BS), e.g. a Radio Base Station (RBS), which sometimes may be referredto as e.g., gNB, evolved Node B (“eNB”), “eNodeB”, “NodeB”, “B node”, orBTS (Base Transceiver Station), depending on the technology andterminology used. The base stations may be of different classes such ase.g. Wide Area Base Stations, Medium Range Base Stations, Local AreaBase Stations and Home Base Stations, based on transmission power andthereby also cell size. A cell is the geographical area where radiocoverage is provided by the base station at a base station site. Onebase station, situated on the base station site, may serve one orseveral cells. Further, each base station may support one or severalcommunication technologies. The wireless communications network may alsobe a non-cellular system, comprising network nodes which may servereceiving nodes, such as wireless devices, with serving beams. In 3rdGeneration Partnership Project (3GPP) Long Term Evolution (LTE), basestations, which may be referred to as eNodeBs or even eNBs, may bedirectly connected to one or more core networks. In the context of thisdisclosure, the expression Downlink (DL) may be used for thetransmission path from the base station to the wireless device. Theexpression Uplink (UL) may be used for the transmission path in theopposite direction i.e., from the wireless device to the base station.

The so-called 5G system, from a radio perspective started to bestandardized in 3GPP, and New Radio (NR) is the name for the radiointerface. One of the characteristics is that the frequency range goingto higher frequencies than LTE, e.g., above 6 GHz, where it is known tohave more challenging propagation conditions such as a higherpenetration loss. To mitigate some of these effects, multi-antennatechnologies such as beamforming will be massively used. Yet another NRcharacteristic is the use of multiple numerologies in DL and UL in acell or for a UE and/or in different frequency bands. Yet anothercharacteristic is the possibility to enable shorter latencies. NRarchitecture is being discussed in 3GPP. In the current concept, gNBdenotes NR base station (BS) (one NR BS may correspond to one or moretransmission/reception points).

The 3GPP work on “Licensed-Assisted Access” (LAA) intends to allow LTEequipment to also operate in the unlicensed radio spectrum. Candidatebands for LTE operation in the unlicensed spectrum include 5 GHz, 3.5GHz, etc. The unlicensed spectrum is used as a complement to thelicensed spectrum or allows a completely standalone operation.

For the case of unlicensed spectrum used as a complement to the licensedspectrum, devices connect in the licensed spectrum (primary cell orPCell) and use carrier aggregation to benefit from additionaltransmission capacity in the unlicensed spectrum (secondary cell orSCell). The carrier aggregation (CA) framework allows to aggregate twoor more carriers with the condition that at least one carrier (orfrequency channel) is in the licensed spectrum and at least one carrieris in the unlicensed spectrum. In the standalone (or completelyunlicensed spectrum) mode of operation, one or more carriers areselected solely in the unlicensed spectrum.

Regulatory requirements, however, may not permit transmissions in theunlicensed spectrum without prior channel sensing, transmission powerlimitations or imposed maximum channel occupancy time. Since theunlicensed spectrum may need to be shared with other radios of similaror dissimilar wireless technologies, a so called listen-before-talk(LBT) method may need to be applied. LBT involves sensing the medium fora pre-defined minimum amount of time and backing off if the channel isbusy. Due to the centralized coordination and dependency of wirelessdevices on the radio network node, such as eNB, for channel access inLTE operation and imposed LBT regulations, LTE uplink (UL) performanceis especially hampered. UL transmission is becoming more and moreimportant with user-centric applications and the need for pushing datato cloud.

Today, the unlicensed 5 GHz spectrum is mainly used by equipmentimplementing the IEEE 802.11 Wireless Local Area Network (WLAN)standard. This standard is known under its marketing brand “Wi-Fi” andallows completely standalone operation in the unlicensed spectrum.Unlike the case in LTE, Wi-Fi terminals can asynchronously access themedium and thus show better UL performance characteristics especially incongested network conditions.

Long Term Evolution (LTE) uses Orthogonal Frequency DivisionMultiplexing (OFDM) in the downlink and discrete fourier transform(DFT)-spread OFDM, also referred to as single-carrier Frequency divisionmultiple access (FDMA), in the uplink. The basic LTE downlink physicalresource can thus be seen as a time-frequency grid as illustrated inFIG. 1 where each resource element corresponds to one OFDM subcarrierduring one OFDM symbol interval. The uplink subframe has the samesubcarrier spacing as the downlink and the same number of SC-FDMAsymbols in the time domain as OFDM symbols in the downlink.

In the time domain, LTE downlink transmissions are organized into radioframes of 10 ms, each radio frame consisting of ten equally-sizedsubframes of length Tsubframe=1 ms as shown in FIG. 2. Each subframecomprises two slots of duration 0.5 ms each, and the slot numberingwithin a frame ranges from 0 to 19. For normal cyclic prefix, onesubframe consists of 14 OFDM symbols. The duration of each symbol isapproximately 71.4 μs.

Furthermore, the resource allocation in LTE is typically described interms of resource blocks, where a resource block corresponds to one slot(0.5 ms) in the time domain and 12 contiguous subcarriers in thefrequency domain. A pair of two adjacent resource blocks in timedirection (1.0 ms) is known as a resource block pair. Resource blocksare numbered in the frequency domain, starting with 0 from one end ofthe system bandwidth.

Downlink transmissions are dynamically scheduled, i.e., in each subframethe radio network node transmits control information about whichwireless devices data is transmitted to and upon which resource blocksthe data is transmitted, in the current downlink subframe. This controlsignalling is typically transmitted in the first 1, 2, 3 or 4 OFDMsymbols in each subframe and the number n=1, 2, 3 or 4 is known as theControl Format Indicator (CFI). The downlink subframe also containscommon reference symbols, which are known to the receiver and used forcoherent demodulation of e.g. the control information. A downlink systemwith CFI=3 OFDM symbols as control is illustrated in FIG. 3. Thereference symbols shown in FIG. 3 are the cell specific referencesymbols (CRS) and are used to support multiple functions including finetime and frequency synchronization and channel estimation for certaintransmission modes.

Uplink transmissions are dynamically scheduled, i.e., in each downlinksubframe the radio network node transmits control information aboutwhich wireless devices should transmit data to the radio network node insubsequent subframes, and upon which resource blocks the data istransmitted. The uplink resource grid is comprised of data and uplinkcontrol information in the Physical Uplink Shared Channel (PUSCH),uplink control information in the Physical Uplink Control Channel(PUCCH), and various reference signals such as demodulation referencesignals (DMRS) and sounding reference signals (SRS). DMRS are used forcoherent demodulation of PUSCH and PUCCH data, whereas SRS is notassociated with any data or control information but is generally used toestimate the uplink channel quality for purposes of frequency-selectivescheduling. An example uplink subframe is shown in FIG. 4. Note that ULDMRS and SRS are time-multiplexed into the UL subframe, and SRS arealways transmitted in the last symbol of a normal UL subframe. The PUSCHDMRS is transmitted once every slot for subframes with normal cyclicprefix, and is located in the fourth and eleventh SC-FDMA symbols.

From LTE Rel-11 onwards, DL or UL resource assignments can also bescheduled on the enhanced Physical Downlink Control Channel (EPDCCH).For Rel-8 to Rel-10 only the Physical Downlink Control Channel (PDCCH)is available. Resource grants are wireless device specific and areindicated by scrambling the downlink control information (DCI) CyclicRedundancy Check (CRC) with the UE-specific cell specific Radio NetworkTemporary Identifier (C-RNTI) identifier. A unique C-RNTI is assigned bya cell to every wireless device associated with it, and can take valuesin the range 0001-FFF3 in hexadecimal format. A wireless device uses thesame C-RNTI on all serving cells.

Scheduled LTE Uplink Scheme. In LTE the uplink access is typicallycontrolled by a radio network node, i.e., scheduled. In this case thewireless device would report to the radio network node when data isavailable to be transmitted, e.g., by sending a scheduling request (SR)message. Based on this, the radio network node may grant the resourcesand relevant information to the wireless device in order to carry outthe transmission of a certain size of data. The assigned resources arenot necessarily sufficient for the wireless device to transmit all theavailable data. Therefore, it is possible that the wireless device sendsa buffer status report (BSR) control message in the granted resources,in order to inform the radio network node about the correct size andupdated size of the data waiting for transmission. Based on that, theradio network node may further grant the resources to carry on with thewireless device uplink transmission of the corrected size of data.

In more detail, every time new data arrives at the wireless device'sempty buffer, the following procedure may need to be performed:

1. Using Physical Uplink Control Channel (PUCCH), the wireless deviceinforms the network that it needs to transmit data by sending aScheduling Request (SR) indicating that it needs uplink access. Thewireless device has a periodic timeslots for SR transmissions (typicallyon a 5, 10, or 20 ms interval).

2. Once the eNB receives the SR request bit, it responds with a small“uplink grant” that is just large enough to communicate the size of thepending buffer. The reaction to this request typically takes 3 ms.

3. After the wireless device receives and processes (takes about 3 ms)its first uplink grant, it typically sends a Buffer Status Report (BSR),that is, a MAC Control Element (MAC CE) used to provide informationabout the amount of pending data in the uplink buffer of the wirelessdevice. If the grant is big enough, the wireless device sends data fromits buffer within this transmission as well. Whether the BSR is sentdepends also on conditions specified in e.g. 3GPP TS 36.321.

4. The radio network node receives the BSR message, allocates thenecessary uplink resources and sends back another uplink grant that willallow the wireless device to drain its buffer.

Adding it all up, about 16 ms (+time to wait for PUCCH transmissionopportunity) of delay can be expected between data arrival at the emptybuffer in the wireless device and reception of this data in the radionetwork node.

In case the wireless device is not radio resource control (RRC)connected in LTE or lost its uplink synchronization since it did nottransmit or receive anything for a certain time, the wireless devicewould use the random access procedure to connect to the network, obtainsynchronization and also send the SR. If this is the case the procedureuntil the data can be sent would take even longer than the SRtransmission on PUCCH.

Downlink Control Information (DCI) for Scheduling LTE UplinkTransmission

In the LTE system, the transmission formats and parameters arecontrolled by the radio network node. Such downlink control information(DCI) typically contains

-   -   Resources allocated for UL transmission (including whether        frequency hopping is applied).    -   Modulation and coding scheme (MCS)    -   Redundancy versions (RV)    -   New data indicator (NDI)    -   Transmit power control command    -   Information about demodulation reference symbol (DMRS)    -   In case of cross-carrier scheduling, the target carrier index is        also included.    -   Other applicable control information on UL transmissions

The DCI is first protected by a 16-bit CRC. The CRC bits are furtherscrambled by the wireless device assigned identity such as C-RNTI. TheDCI and scrambled CRC bits are further protected by convolutionalcoding. The encoded bits are transmitted from the radio network node tothe wireless device using either PDCCH or EPDCCH.

Hybrid automatic repeat request (HARQ) design: For frequency divisionduplex (FDD): Asynchronous HARQ is used for Downlink. This means thatthe 8 HARQ processes may be used in any order. Nevertheless, the radionetwork node sends, e.g. Process ID, and redundancy value (RV), in PDCCHso the wireless device 10 may know which HARQ process it received duringa certain subframe.

For uplink Synchronous HARQ is used. The wireless device has to use thesame HARQ process number every 8 subframes. Since a specific HARQprocess ID is used at specific subframe, the receiver (eNode B) knowsexactly which HARQ process comes when. And the radio network node mayalso know about RV because UL Grant (DCI 0) from the radio network nodemay specify RV using MCS field. HARQ has two modes of operation:Adaptive and Non-Adaptive HARQ. With Adaptive, the wireless device doesnot care about “HARQ feedback Physical Hybrid-ARQ Indicator Channel(PHICH)”, it retransmit based on DCI 0 information. While non-adaptiveretransmission follows a HARQ feedback, e.g. PHICH=NACK, without a DCI 0and the wireless device retransmits using the same downlink controlinformation (RB, MCS, etc) as the initial transmission.

For time division duplex, TDD: One UL subframe acknowledgments ofmultiple DL transport blocks is supported since some TDD configurationcontain unequal number of DL/UL subframes. The PUCCH design for TDD isdifferent than FDD, since for TDD it may be required to carry multipleacknowledgements (ACK) per UE. An alternative mechanism that allows forreuse of the FDD PUCCH design is also provided in LTE TDD, where by theacknowledgment corresponding to multiple DL transmissions are groupusing a logical “AND” operation to form a single acknowledgment whetherzero or more than zero blocks were received in error. However, this mayrequire retransmission of all the HARQ processes if at least one of themis non-acknowledged (NACK).

In typical deployments of Wireless Local Area Network (WLAN), carriersense multiple access with collision avoidance (CSMA/CA) is used formedium access. This means that the channel is sensed to perform a clearchannel assessment (CCA), and a transmission is initiated only if thechannel is declared as Idle. In case the channel is declared as Busy,the transmission is essentially deferred until the channel is deemed tobe Idle.

A general illustration of the listen before talk (LBT) mechanism ofWi-Fi is shown in FIG. 5. After a Wi-Fi station A transmits a data frameto a station B, station B shall transmit the ACK frame back to station Awith a delay of 16 μs. Such an ACK frame is transmitted by station Bwithout performing a LBT operation. To prevent another stationinterfering with such an ACK frame transmission, a station shall deferfor a duration of 34 μs, referred to as distributed coordinationfunction inter-frame space (DIFS), after the channel is observed to beoccupied before assessing again whether the channel is occupied.Therefore, a station that wishes to transmit first performs a CCA bysensing the medium for a fixed duration DIFS. If the medium is idle thenthe station assumes that it may take ownership of the medium and begin aframe exchange sequence. If the medium is busy, the station waits forthe medium to go idle, defers for DIFS, and waits for a further randombackoff period.

In the above basic protocol, when the medium becomes available, multipleWi-Fi stations may be ready to transmit, which can result in collision.To reduce collisions, stations intending to transmit select a randombackoff counter and defer for that number of slot channel idle times.The random backoff counter is selected as a random integer drawn from auniform distribution over the interval of zero to contention window i.e.[0, CW]. The default size of the random backoff contention window,CWmin, is set in the IEEE specs. Note that collisions can still happeneven under this random backoff protocol when there are many stationscontending for the channel access. Hence, to avoid recurring collisions,the backoff contention window size CW is doubled whenever the stationdetects a collision of its transmission up to a limit, CWmax, also setin the IEEE specs. When a station succeeds in a transmission withoutcollision, it resets its random backoff contention window size back tothe default value CWmin.

Load-based clear channel assessment in Europe regulation EN 301.893. Fora device not utilizing the Wi-Fi protocol, EN 301.893, v. 1.7.1 providesthe following requirements and minimum behaviour for the load-basedclear channel assessment.

1) Before a transmission or a burst of transmissions on an OperatingChannel, the equipment shall perform a Clear Channel Assessment (CCA)check using “energy detect” i.e. detecting energy above a threshold. Theequipment shall observe the Operating Channel(s) for the duration of theCCA observation time which shall be not less than 20 μs. The CCAobservation time used by the equipment shall be declared by themanufacturer. The Operating Channel shall be considered occupied if theenergy level in the channel exceeds the threshold corresponding to thepower level given in point 5 below. If the equipment finds the channelto be clear, it may transmit immediately (see point 3 below).

2) If the equipment finds an Operating Channel occupied, it shall nottransmit in that channel. The equipment shall perform an Extended CCAcheck in which the Operating Channel is observed for the duration of arandom factor N multiplied by the CCA observation time. N defines thenumber of clear idle slots resulting in a total Idle Period that need tobe observed before initiation of the transmission. The value of N shallbe randomly selected in the range 1 . . . q every time an Extended CCAis required and the value stored in a counter. The value of q isselected by the manufacturer in the range 4 . . . 32. This selectedvalue shall be declared by the manufacturer (see clause 5.3.1 q)). Thecounter is decremented every time a CCA slot is considered to be“unoccupied”. When the counter reaches zero, the equipment may transmit.

3) The total time that an equipment makes use of an Operating Channel isthe Maximum Channel Occupancy Time which shall be less than ( 13/32)×qms, with q as defined in point 2 above, after which the device shallperform the Extended CCA described in point 2 above.

4) The equipment, upon correct reception of a packet which was intendedfor this equipment, can skip CCA and immediately (see note 4) proceedwith the transmission of management and control frames (e.g. ACK andBlock ACK frames). A consecutive sequence of transmissions by theequipment, without it performing a new CCA, shall not exceed the MaximumChannel Occupancy Time as defined in point 3 above.

NOTE 4: For the purpose of multi-cast, the ACK transmissions (associatedwith the same data packet) of the individual devices are allowed to takeplace in a sequence.

5) The energy detection threshold for the CCA shall be proportional tothe maximum transmit power (PH) of the transmitter: for a 23 dBme.i.r.p. transmitter the CCA threshold level (TL) shall be equal orlower than −73 dBm/MHz at the input to the receiver (assuming a 0 dBireceive antenna). For other transmit power levels, the CCA thresholdlevel TL shall be calculated using the formula: TL=−73 dBm/MHz+23−PH(assuming a 0 dBi receive antenna and PH specified in dBm e.i.r.p.).

An example to illustrate the EN 301.893 LBT is provided in FIG. 6.

Licensed-assisted access (LAA) to unlicensed spectrum using LTE. Up tonow, the spectrum used by LTE is dedicated to LTE. This has theadvantage that LTE system does not need to care about the coexistenceissue and the spectrum efficiency can be maximized. However, thespectrum allocated to LTE is limited which cannot meet the everincreasing demand for larger throughput from applications/services.Therefore, Rel-13 LAA extended LTE to exploit unlicensed spectrum inaddition to licensed spectrum. Unlicensed spectrum can, by definition,be simultaneously used by multiple different technologies. Therefore,LTE may need to consider the coexistence issue with other systems suchas IEEE 802.11 (Wi-Fi). Operating LTE in the same manner in unlicensedspectrum as in licensed spectrum can seriously degrade the performanceof Wi-Fi as Wi-Fi will not transmit once it detects the channel isoccupied.

Furthermore, one way to utilize the unlicensed spectrum reliably is totransmit essential control signals and channels on a licensed carrier.That is, as shown in FIG. 7, a wireless device is connected to a PCellin the licensed band and one or more SCells in the unlicensed band. Inthis application we denote a secondary cell in unlicensed spectrum aslicensed-assisted access secondary cell (LAA SCell). In the case ofstandalone operation as in MulteFire, no licensed cell is available foruplink control signal transmissions.

Unscheduled Uplink for LAA/multeFire

To improve the UL performance, the main target may be to lower the ULlatency by reducing the control signalling related to scheduling thatprecede every UL transmission. In addition, UL transmissions may need tonot be subject to repeated subsequent LBTs when operating in unlicensedspectrum.

To reduce the control signalling overhead, LTE provides the option to dosemi-persistent scheduling (SPS) which is the basis of autonomous ULoperation. The wireless device is configured to transmit onpre-allocated resources. When UL data arrives, the wireless device canstart transmission immediately according to the configured resourceswithout the need to send an SR or waiting for the grant as shown in FIG.8. Autonomous UL feature is based on semi-persistent scheduling.

HARQ Design

Autonomous uplink (AUL) on LAA SCells following SPS-like behaviour (RRCconfiguration and DCI activation). One foremost issue when AUL based onSPS-like feature is supported is the UL HARQ design. In SPS, when thefeature is activated, the radio network node proactively sends NACK onPHICH for the SPS resource until UL data has been decoded. The SPS HARQdesign is based on synchronous UL HARQ. The data reception and thefeedback transmission have a fixed time relation of 4 subframes. Thisdesign might work if the feedback is sent on the primary licensedcarrier that is always available. Nevertheless, with the intention ofoverbooking the resources on the LAA unlicensed carrier, it is not clearhow PHICH collisions can be avoided. On the other hand, the same designis not applicable for unlicensed carrier, first, PHICH is not availableon LAA secondary cells, second, it highly utilizes the unlicensedchannel, and third, this kind of synchronous behaviour with fixed timingbetween data transmission and feedback reception cannot be deployed onunlicensed channel due to uncertainty of channel availability.

In eLAA, any uplink transmission (new transmission or retransmission) isscheduled via UL grant through (e)PDCCH. This works well for scheduledaccess where the radio network node is aware of wireless device bufferand every failed UL attempt. With autonomous UL, the radio network nodedoes not know when to expect an UL transmission. There is a chance thatthe UL transmission is missed by the radio network node. In this case,the radio network node will not request a retransmission. Scheduledtransmission via UL grant through (e)PDCCH is not sufficient in case ofAUL transmissions.

Asynchronous UL HARQ operation was considered beneficial for eLAA inparticular when retransmissions are blocked and postponed due to LBT.The following situations might happen in case of AUL:

-   -   The radio network node may fail to transmit the feedback at n+4        due to failed LBT. Therefore, the timing relation between AUL        transmission and corresponding UL HARQ feedback should not be        fixed. Potentially, the HARQ feedback may include pending        feedback for several uplink transmissions from the same wireless        device.    -   Similarly, timing relationship between UL HARQ feedback and        corresponding retransmission should not be fixed. Unlike        scheduled UL, the HARQ process information in case of AUL are        not indicated to the wireless device as in the scheduled UL.

Therefore, Asynchronous AUL HARQ feedback and retransmissions aresupported for AUL transmissions, meaning that:

(1) Timing relationship between AUL transmission and corresponding ULHARQ feedback is not fixed.

(2) Timing relationship between UL HARQ feedback and correspondingretransmission is not fixed.

CW Adjustment

Wireless device contention window (CW) update procedure is the same asdefined for Uplink Type 1 Channel access for eLAA [36.213, Section15.2.2], except for possible availability of explicit HARQ feedback.Additionally, a common wireless device CW is maintained for scheduled ULand AUL.

The reference subframe is defined as the first subframe of the mostrecent UL (scheduled based uplink (SUL) or AUL) burst of contiguoussubframes that is transmitted after performing a category 4 LBTprocedure at least 4 subframes prior to a UL grant reception or an AULDownlink feedback information. The HARQ ID of the reference subframe isHARQ_ID_ref.

Regarding the CW size (CWS) adaptation, i.e., increase/reset, if thewireless device receives an UL grant or an AUL-downlink feedbackindication (DFI), the contention window size for all the priorityclasses is adjusted as following:

-   -   The CWS at the wireless device is reset to minimum size for all        the priority classes if:    -   An UL grant is received and the new data indicator (NDI) bit for        at least one of the active HARQ processes (i.e. transport block        (TB) not disabled) associated with HARQ_ID_ref is toggled; OR    -   An AUL-DFI is received and indicates ACK for at least one of the        active HARQ processes (i.e. TB not disabled) associated with        HARQ_ID_ref    -   The CWS of all priority classes at the wireless device is        increased to the next higher value if:    -   An UL grant is received and the NDI bit(s) of all the active        HARQ processe(s) for the reference subframe are not toggled; OR    -   An UL grant is received and does not schedule any active HARQ        process (i.e. TB not disabled) for the reference subframe; OR    -   An AUL-DFI is received which does not indicate ACK for at least        one of the active HARQ processes for the reference subframe.    -   The CWS is reset to the minimum value if the maximum CWS is used        for K consecutive LBT attempts for transmission only for the        priority class for which maximum CWS is used for K consecutive        LBT attempts.    -   K is selected by wireless device implementation from the set of        values from (1, . . . , 8).    -   The NDI value(s) received in the UL grant or the HARQ-ACK        value(s) received in the earliest AUL-DFI after n_ref+3 is used        for adjusting the CWS, where n_ref is the reference subframe.    -   HARQ_ID_ref is the HARQ ID of n_ref.

Existing methods for performing unscheduled uplink transmissions mayresult in wasted resources, and/or increased latency.

SUMMARY

It is an object of embodiments herein to enable communication, such asenable unscheduled uplink transmissions, in a wireless communicationsnetwork in an efficient manner.

Several embodiments are comprised herein. It should be noted that theexamples herein are not mutually exclusive. Components from oneembodiment may be tacitly assumed to be present in another embodimentand it will be obvious to a person skilled in the art how thosecomponents may be used in the other exemplary embodiments.

A first aspect relates to a method, performed by a first communicationnode is described herein. The method may be understood to be forinitiating a sensing procedure. The first communication node operates inthe wireless communications network. The first communication node, suchas a UE, adjusts a value of a Contention Window (CW) based on one ormore criteria. The first communication node adjusts the value of the CW,from a first value to a second value. The second value is a highervalue, e.g., a first higher value, than the first value. The adjusting1001 is performed before a sensing procedure performed prior to atransmission of an Uplink (UL) burst to a second communication node. Theadjusting is based on one or more feedback timers having expired at atime of performing the sensing procedure in the absence of: a) areceived UL grant from the second communication node, or b) a downlinkfeedback from the second communication node for an Autonomous Uplink(AUL) transmission from the first communication node. The firstcommunication node further, following the adjusting of the value,initiates the sensing procedure performed prior to the transmission ofthe UL burst to the second communication node, wherein the sensingprocedure uses the adjusted second value of the CW.

According to another aspect the object is achieved by providing a firstcommunication node configured to operate in a wireless communicationsnetwork. The first communication node is configured to adjust a value ofa CW from a first value to a second value, the second value being ahigher value than the first value. The adjustment of the value is basedon one or more feedback timers having expired at a time of performing asensing procedure in the absence of: a) a received uplink, UL, grantfrom a second communication node, or b) a downlink feedback from thesecond communication node for an AUL transmission from the firstcommunication node. The first communication node is further configuredto, following adjusting the value, initiate the sensing procedureperformed prior to a transmission of an UL burst to the secondcommunication node, wherein the sensing procedure uses the adjustedvalue of the CW.

It is furthermore provided herein a computer program product comprisinginstructions, which, when executed on at least one processor, cause theat least one processor to carry out any of the methods above, asperformed by the first communication node. It is additionally providedherein a computer-readable storage medium, having stored thereon acomputer program product comprising instructions which, when executed onat least one processor, cause the at least one processor to carry outthe method according to any of the methods above, as performed by thefirst communication node.

By having the first communication node adjusting the value of the CWbased on e.g. a first number of feedback timers having expired at thetime of performing the sensing procedure in the absence of the receivedUL grant or the downlink feedback for the AUL transmission, the firstcommunication node is enabled to initiate the sensing procedure with amore efficient and optimized value of the CW, for example, avoidingunnecessarily increasing the CW, and therefore saving resources and e.g.reducing latency of transmissions. Using one or more feedback timershaving expired may allow to make certain assumptions on the likelihoodthat the second communication node may have received the respective ULbursts previously transmitted by the first communication node to thesecond communication node, e.g., due to radio conditions. Embodimentsherein thus provide ways of enabling communication in an efficient e.g.resource efficient, manner.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of embodiments herein are described in more detail withreference to the accompanying drawings, and according to the followingdescription.

FIG. 1 is a schematic diagram depicting the LTE downlink physicalresource.

FIG. 2 is a schematic diagram depicting the LTE time-domain structure.

FIG. 3 is a schematic diagram depicting a Downlink subframe.

FIG. 4 is a schematic diagram depicting an Uplink subframe.

FIG. 5 is a schematic diagram depicting an illustration of listen beforetalk (LBT) in Wi-Fi.

FIG. 6 is a schematic diagram depicting an illustration of listen beforetalk (LBT) in EN 301.893.

FIG. 7 is a schematic diagram depicting a Licensed-assisted access (LAA)to unlicensed spectrum using LTE carrier aggregation.

FIG. 8 is a schematic diagram depicting an LTE UL SPS operation.

FIG. 9 is a schematic diagram illustrating a wireless communicationsnetwork, according to embodiments herein.

FIG. 10 is a flowchart depicting a method in a first communication node,according to embodiments herein.

FIG. 11 is a schematic diagram depicting non-limiting examples of themethod in a first communication node according to embodiments herein,for the scenario One/Multiple timer expire(s).

FIG. 12 is a schematic diagram depicting non-limiting examples of themethod in a first communication node according to embodiments herein,for the scenario Timer expires+late feedback.

FIG. 13 is a schematic diagram depicting non-limiting examples of themethod in a first communication node according to embodiments herein,for the scenario Multiple Timer expire+late feedback.

FIG. 14 is a schematic block diagram illustrating two non-limitingexamples, a) and b), of a first communication node, according toembodiments herein.

FIG. 15 is a schematic block diagram illustrating a telecommunicationnetwork connected via an intermediate network to a host computer,according to embodiments herein.

FIG. 16 is a generalized block diagram of a host computer communicatingvia a base station with a user equipment over a partially wirelessconnection, according to embodiments herein.

FIG. 17 is a flowchart depicting embodiments of a method in acommunications system including a host computer, a base station and auser equipment, according to embodiments herein.

FIG. 18 is a flowchart depicting embodiments of a method in acommunications system including a host computer, a base station and auser equipment, according to embodiments herein.

FIG. 19 is a flowchart depicting embodiments of a method in acommunications system including a host computer, a base station and auser equipment, according to embodiments herein.

FIG. 20 is a flowchart depicting embodiments of a method in acommunications system including a host computer, a base station and auser equipment, according to embodiments herein.

DETAILED DESCRIPTION

As part of the development of embodiments herein, one or more problemswith the existing technology will first be identified and discussed.

For scheduled UL access, the wireless device is fully controlled by theradio network node, in terms of the time the radio network nodeschedules the wireless device and the time when the radio network nodedecides to send feedback for previous UL transmissions. Therefore, thecase in which the wireless device initiates Category 4 LBT UL (SUL/AUL)transmission on its own without indication from the radio network nodedid not exist before.

However, with AUL, the wireless device is in control of when to initiatea CAT4 LBT and which HARQ process to transmit. Therefore, the rules forcontention window adjustments may need to be extended to include thecase in which the wireless device initiates Category 4 LBT ULtransmission before reception of feedback for previous Category 4 LBT ULtransmission.

Certain aspects of the present disclosure and their embodiments mayprovide solutions to this challenge or other challenges. There are,proposed herein, various embodiments which address one or more of theissues disclosed herein.

Embodiments herein may be understood to address this problem in existingmethods by providing a method of contention window adjustment for AUL incase of no feedback reception.

Embodiments herein may be understood to be related to methods forcontention window adjustment for the case no feedback reception.

Particular embodiments herein may apply, e.g., to LAA, MulteFire, andNR-U when autonomous UL mode is activated.

Some of the embodiments contemplated will now be described more fullyhereinafter with reference to the accompanying drawings, in whichexamples are shown. In this section, the embodiments herein will beillustrated in more detail by a number of exemplary embodiments. Otherembodiments, however, are contained within the scope of the subjectmatter claimed herein. The disclosed subject matter should not beconstrued as limited to only the embodiments set forth herein; rather,these embodiments are provided by way of example to convey the scope ofthe subject matter to those skilled in the art. It should be noted thatthe exemplary embodiments herein are not mutually exclusive. Componentsfrom one embodiment may be tacitly assumed to be present in anotherembodiment and it will be obvious to a person skilled in the art howthose components may be used in the other exemplary embodiments.

Note that although terminology from LTE/5G has been used in thisdisclosure to exemplify the embodiments herein, this should not be seenas limiting the scope of the embodiments herein to only theaforementioned system. Other wireless systems with similar features, mayalso benefit from exploiting the ideas covered within this disclosure.

FIG. 9 depicts a non-limiting example of a wireless communicationsnetwork 100, sometimes also referred to as a wireless communicationssystem, cellular radio system, or cellular network, in which embodimentsherein may be implemented. The wireless communications network 100 mayenable transmissions in an autonomous UL mode. The wirelesscommunications network 100 may typically be a 5G system, 5G network,NR-U or Next Gen System or network, LAA, MulteFire. The wirelesscommunications network 100 may alternatively be a younger system than a5G system The wireless communications network 100 may support othertechnologies such as, for example, Long-Term Evolution (LTE),LTE-Advanced/LTE-Advanced Pro, e.g. LTE Frequency Division Duplex (FDD),LTE Time Division Duplex (TDD), LTE Half-Duplex Frequency DivisionDuplex (HD-FDD), LTE operating in an unlicensed band, NB-loT. Thus,although terminology from 5G/NR and LTE may be used in this disclosureto exemplify embodiments herein, this should not be seen as limiting thescope of the embodiments herein to only the aforementioned systems.

The wireless communications network 100 comprises a plurality ofcommunication nodes, whereof a first communication node 101 and a secondcommunication node 102 are depicted in the non-limiting example of FIG.9. The first communication node 101 may be considered as a nodesupporting transmission in the autonomous UL mode. As depicted in thenon-limiting example of FIG. 9, the first communication node 101 maytypically be a wireless device as a wireless device 130 as describedbelow. As also depicted in the non-limiting example of FIG. 9, thesecond communication node 102 may typically be a radio network node as anetwork node 110 as described below, or another wireless device in aDevice-to-Device communication with the first communication node 101.

The wireless communications network 100 comprises a plurality of networknodes, whereof a network node 110 is depicted in the non-limitingexample of FIG. 9. The network node 110 may be a radio network node,such as a radio base station, or any other network node with similarfeatures capable of serving a wireless device, such as a user equipmentor a machine type communication device, in the wireless communicationsnetwork 100. In typical embodiments, the network node 110 may be atransmission point operating on NR, for example a New Radio (NR) NodeB(gNB). In some examples, the network node 110 may be radio base stationoperating on LTE, such as an eNB.

The wireless communications network 100 covers a geographical area whichmay be divided into cell areas, wherein each cell area may be served bya network node, although, one network node may serve one or severalcells. The wireless communications network 100 comprises at least a cell120. In the non-limiting example depicted in FIG. 9, the network node110 serves the cell 120. The network node 110 may be of differentclasses, such as, e.g., macro base station (BS), home BS or pico BS,based on transmission power and thereby also cell size. The network node110 may be directly connected to one or more core networks, which arenot depicted in FIG. 9 to simplify the Figure. In some examples, thenetwork node 110 may be a distributed node, such as a virtual node inthe cloud, and it may perform its functions entirely on the cloud, orpartially, in collaboration with a radio network node.

A plurality of wireless devices are located in the wirelesscommunication network 100, whereof a wireless device 130, which may alsobe referred to as a device, is depicted in the non-limiting example ofFIG. 9. The wireless device 130, e.g., a 5G UE, may be a wirelesscommunication device which may also be known as e.g., a UE, a mobileterminal, wireless terminal and/or mobile station, a mobile telephone,cellular telephone, or laptop with wireless capability, just to mentionsome further examples. The wireless device 130 may be, for example,portable, pocket-storable, hand-held, computer-comprised, or avehicle-mounted mobile device, enabled to communicate voice and/or data,via the RAN, with another entity, such as a server, a laptop, a PersonalDigital Assistant (PDA), or a tablet, Machine-to-Machine (M2M) device,device equipped with a wireless interface, such as a printer or a filestorage device, modem, or any other radio network unit capable ofcommunicating over a radio link in a communications system. The wirelessdevice 130 comprised in the wireless communications network 100 isenabled to communicate wirelessly in the wireless communications network100. The communication may be performed e.g., via a RAN, and possiblythe one or more core networks, which may be comprised within thewireless communications network 100.

The first communication node 101 may be configured to communicate in thewireless communications network 100 with the second communication node102 over a link 140, e.g., a radio link, although communication overmore links may be possible.

Generally, all terms used herein are to be interpreted according totheir ordinary meaning in the relevant technical field, unless adifferent meaning is clearly given and/or is implied from the context inwhich it is used. All references to a/an/the element, apparatus,component, means, step, etc. are to be interpreted openly as referringto at least one instance of the element, apparatus, component, means,step, etc., unless explicitly stated otherwise. The steps of any methodsdisclosed herein do not have to be performed in the exact orderdisclosed, unless a step is explicitly described as following orpreceding another step and/or where it is implicit that a step mustfollow or precede another step. Any feature of any of the embodimentsdisclosed herein may be applied to any other embodiment, whereverappropriate. Likewise, any advantage of any of the embodiments may applyto any other embodiments, and vice versa. Other objectives, features andadvantages of the enclosed embodiments will be apparent from thefollowing description.

In general, the usage of “first”, “second”, “third”, “fourth” and/or“fifth” herein may be understood to be an arbitrary way to denotedifferent elements or entities, and may be understood to not confer acumulative or chronological character to the nouns they modify, unlessotherwise noted, based on context.

Several embodiments are comprised herein. It should be noted that theexamples herein are not mutually exclusive. Components from oneembodiment may be tacitly assumed to be present in another embodimentand it will be obvious to a person skilled in the art how thosecomponents may be used in the other exemplary embodiments.

More specifically, the following are embodiments related to a wirelessdevice, such as the wireless device 130, e.g., a 5G UE.

The first communication node 101 embodiments relate to FIG. 10, FIG. 14,and FIGS. 15-20.

A method, performed by the first communication node 101 is describedherein. The method may be understood to be for initiating a sensingprocedure. The first communication node 101 operates in the wirelesscommunications network 100. The method may comprise the followingactions.

In some embodiments all the actions may be performed. In someembodiments, one or more actions may be performed. One or moreembodiments may be combined, where applicable. All possible combinationsare not described to simplify the description. In FIG. 10, optionalactions are indicated with dashed lines. Some actions may be performedin a different order than that shown in FIG. 10.

Action 1001. The first communication node 101 adjusts a value of aContention Window (CW) based on one or more criteria. The firstcommunication node such as the wireless device 130 adjusts the value ofthe CW from a first value to a second value. The second value is ahigher value, e.g., a first higher value, than the first value. Theadjusting 1001 may be performed before a sensing procedure to beperformed prior to a transmission of an Uplink (UL), burst to the secondcommunication node 102. The first communication node 101 adjusts thevalue based on one or more feedback timers having expired at a time ofperforming a sensing procedure in the absence of: a) a received UL grantfrom the second communication node 102, or b) a downlink feedback fromthe second communication node 102 for an AUL transmission from the firstcommunication node. The value of the CW may be adjusted for all priorityclasses at the first communication node 101. At the time of performingthe sensing procedure, the one or more feedback timers may have expiredin the absence of any downlink transmission from the secondcommunication node 102, the higher value may be increased once to a nexthigher value. The next higher value may be dependent on number ofexpired feedback timers. Alternatively or additionally, at the time ofperforming the sensing procedure, the one or more feedback timers haveexpired, and at least one DL transmission has been received from thesecond communication node 102, wherein the DL transmission being devoidof feedback information, the higher value may be increased to a nexthigher value. The next higher value may be dependent on number ofexpired feedback timers. Each of the feedback timers may correspond to arespective HARQ process corresponding to a respective UL burstpreviously transmitted by the first communication node 101 to the secondcommunication node 102.

The adjusting 1001 may thus be based on:

a first number of feedback timers having expired at a time of performingthe sensing procedure in the absence of: a) a received UL grant from thesecond communication node 102, or b) a downlink feedback from the secondcommunication node 102 for an Autonomous Uplink (AUL). Each of thefeedback timers may correspond to a respective Hybrid Automatic RepeatreQuest (HARQ), process corresponding to a respective UL burstpreviously transmitted by the first communication node 101 to the secondcommunication node 102.

The value of the CW may be understood to relate to, e.g., size of theCW. The size may be e.g., in terms of sensing slots, such as 9 us units.

Each feedback timer may run for a number of time units. For example, thetime units may be subframes or slots, e.g., 6 subframes, or 6 slots inNR.

The sensing procedure may be e.g., a Cat4 LBT.

The first communication node 101 may be configured to perform thisadjusting 1001 action, e.g. by means of an adjusting unit 1401 as shownin FIG. 14 within the first communication node 101, configured toperform this action. The adjusting unit 1401 may be a processor 1407 ofthe first communication node 101, or an application running on suchprocessor. The adjusting may be understood herein as changing, ordetermining.

Action 1002. The first communication node 101 then, following adjustingthe value, initiates the sensing procedure performed prior to thetransmission of the UL burst to the second communication node 102,wherein the sensing procedure uses the adjusted value of the CW. Thus,the first communication node 101 may initiate the sensing procedure tobe performed prior to the transmission of the UL burst to the secondcommunication node 102, based on the adjusted value of the CW. The firstcommunication node 101 may be configured to perform this initiatingaction 1002, e.g. by means of an initiating unit 1402, see FIG. 14,within the first communication node 101, configured to perform thisaction. The initiating unit 1402 may be the processor 1407 of the firstcommunication node 101, or an application running on such processor. Theinitiating may be understood herein as triggering, starting, orenabling. The transmission of the UL burst may be performed via, e.g.,the link 140. The value of the CW may be adjusted for all priorityclasses at the first communication node 101. In some examples in a firstgroup of examples, at the time of performing the sensing procedure, thefirst number of feedback timers may have expired in the absence of anydownlink transmission from the second communication node 102. The firsthigher value may then be increased once to a next higher value. Aparticular example of this is shown in FIG. 11, rows (1) and (2).

In some other examples in the first group of examples, at the at thetime of performing the sensing procedure, the first number of feedbacktimers may have expired, and at least one downlink, DL, transmission mayhave been received from the second communication node 102. The DLtransmission may be devoid of feedback information. The first highervalue may then be increased a second number of times to a next highervalue. A particular example of this is shown in FIG. 11, row (3).

In some examples in a second group of examples, the CW may have beenadjusted, e.g., as per Action 1001, and after the time of performing thesensing procedure and the one or more feedback timers has expired, themethod may further comprise the actions of:

Action 1003. The first communication node 101 may receive at least oneDL transmission from the second communication node 102 comprisingfeedback information. The feedback information may be negative for alatest expired timer.

Thus, the first communication node 101 may receive at least one DLtransmission from the second communication node 102. The firstcommunication node 101 may be configured to perform this receivingaction 1003, e.g., by means of a receiving unit 1403, see FIG. 14,within the first communication node 101, configured to perform thisaction. The receiving unit 1403 may be the processor 1407 of the firstcommunication node 101, or an application running on such processor.

In some examples, the at least one DL transmission may be at least onefirst DL transmission from the second communication node 102. The atleast one first DL transmission may comprise feedback information. Insome examples, the feedback information may be negative for a latestexpired timer.

In some embodiments, the method may further comprise the action of:

Action 1004. The first communication node 101 may, with the proviso thatthe feedback information is negative, use a CW of the second value in afollowing sensing procedure. The first communication node may e.g.refrain from adjusting the value of the CW, based on the received atleast one first DL transmission. The first communication node 101 may beconfigured to perform this refraining action 1004, e.g. by means of arefraining unit 1404, see FIG. 14, within the first communication node101, configured to perform this action. The refraining unit 1404 may bethe processor 1407 of the first communication node 101, or anapplication running on such processor.

A particular example of this Action 1003 and Action 1004 is shown inFIG. 13, row (1).

In some other examples in the second group of examples, the CW may havebeen adjusted, e.g., as per Action 1001, and after the time ofperforming the sensing procedure and the first number of feedback timershas expired, the method may further comprise the actions of:

Action 1003. Alternatively or additionally to action of receivingnegative feedback, the first communication node 101 may receive at leastone DL transmission from the second communication node 102 comprisingfeedback information, wherein the feedback information may be positivefor a latest expired timer. Thus, the first communication node 101 mayreceive the at least one downlink, DL, transmission from the secondcommunication node 102. The first communication node 101 may beconfigured to perform this receiving action 1003, as stated earlier,e.g. by means of the receiving unit 1403 within the first communicationnode 101, configured to perform this action.

In some of these other examples in the second group of examples, the atleast one DL transmission may be at least one at least one second DLtransmission from the second communication node 102. The at least onesecond DL transmission may comprise feedback information. In someexamples, the feedback information may be positive for the latestexpired timer.

In some embodiments, the method may further comprise the action of:

Action 1005. The first communication node 101 may, with the proviso thatthe feedback information is positive, reset the value of the CW, fromthe second value to the first or a third value. The third value may be apreset minimum value. Thus, the first communication node 101 may e.g.reset the value of the CW, from the second value or e.g. to the thirdvalue, based on the received second DL transmission. The firstcommunication node 101 may be configured to perform this resettingaction 1005, e.g. by means of a resetting unit 1405, see FIG. 14, withinthe first communication node 101, configured to perform this action. Theresetting unit 1405 may be the processor 1407 of the first communicationnode 101, or an application running on such processor. The feedbackinformation may be positive when at least one of the following isfulfilled:

-   -   a. all reference subframes are Acknowledged (Acked);    -   b. a latest reference subframe is Acked;    -   c. more than a set number of reference subframes are Acked;    -   d. less than a set number of the reference subframes are        Negatively Acknowledged (Nacked);

The reference subframes correspond to subframes wherein the one or morefeedback timers were initiated.

A particular example of this is shown in FIG. 13, row (2).

In some embodiments, the received at least one DL transmission maycorrespond to (be associated with) a HARQ ID linked to the latestexpired timer.

In a third group of examples, the resetting 1005 may be performed basedon at least one of the following provisos:

-   -   a. all reference subframes are Acknowledged, Acked;    -   b. a latest reference subframe is Acked    -   c. more than a third number of the reference subframes are Acked    -   d. less than a fourth number of the reference subframes are        Negatively Acknowledged, Nacked.

The reference subframes may correspond to subframes wherein the firstnumber of feedback timers were initiated.

Other units 1406 may be comprised in the first communication node 101.

The first communication node 101 may also comprise a client application3332 or a client application unit, which may be configured tocommunicate user data with a host application unit in a host computer3310, e.g., via another link such as 3350.

In FIG. 14, optional units are indicated with dashed boxes.

The first communication node 101 may comprise an interface unit tofacilitate communications between the first communication node 101 andother nodes or devices, e.g., the network node 110, the host computer3310, or any of the other nodes. In some particular examples, theinterface may, for example, include a transceiver configured to transmitand receive radio signals over an air interface in accordance with asuitable standard.

The first communication node 101 may comprise an arrangement as shown inFIG. 14 or in FIG. 16.

Some embodiments herein will now be further described with somenon-limiting examples.

In the following description, any reference to a/the UE may beunderstood to equally refer the first communication node 101; anyreference to a/the eNB may be understood to equally refer the secondcommunication node 102; any reference to a/the CAT4 UL burst may beunderstood to equally refer the UL burst.

One case, yet to be specified, is CW adjustment for the case of noACK/NACK reception. It has been discussed during previous 3GPP meetingsthat the wireless device starts a timer with the start of each CAT4 ULburst and may need to react in response to the timer expiry. In here, weprovide a detailed description of the methods for handling the CW forthe case of no ACK/NACK reception, assuming a timer N=6.

In the examples below the first communication node is exemplified as thewireless device 130 (UE) and the second communication node isexemplified as the network node 110 (eNB),

First Group of Examples: One/Multiple Timer Expire(s)

Example 1 in the first group of examples: Before initiating a new CAT4LBT, if one or multiple timers expire due to no feedback reception, thecontention window size of all priority classes at the wireless device isincreased to the next higher value as shown in case 1 and 2 of FIG. 11.

In another example in the first group of examples, we differentiatebetween the two cases:

1. no DL transmissions from the network node 110 at all (case 2 above):can be due to either UL burst(s) missed by the network node 110, or thenetwork node 110 failed to access the channel to send the feedback. As aresult, the contention window size of all priority classes at thewireless device 130 is increased once to the next higher value

2. DL transmissions occur but the later do not carry any type offeedback (case 3 above): This can be an indication that the UL burst(s)were missed by the network node 110. As a result, the contention windowsize of all priority classes at the wireless device 130 is increased 2*Xtimes, where X is the number of expired timers.

Second Group of Examples: Timer Expires+Late Feedback

feLAA supports flexible timing relationship between AUL transmission andcorresponding UL HARQ feedback. Thereby, it could happen that thewireless device 130 receives a positive “ACK” for the HARQ_ID_ref thatwas assumed “NACK” after the timer expires, as shown in case 1 of FIG.12.

The reference subframe is the first subframe of the most recent UL,SUL/AUL, burst of contiguous subframes that is transmitted afterperforming a category 4 LBT procedure with the following timing:

-   -   At least 4 subframes prior to a UL grant reception or an AUL        Downlink feedback information.    -   For further study (FFS): multiple reference subframes can be        supported.

According to the above, the wireless device 130 may reset the contentionwindow after the reception of the “ACK” in case 1 of FIG. 12. However,this is not true for case (2) of FIG. 12. In fact, according to thedefinition of the reference subframe, the reference subframe for CWadjustment at k+10 would be the transmission at k+3. As a result, the CWat k+10 may need to be doubled from 2*CW to 4*CW. It is not consistentthat the CW is increased upon timer expiry but not corrected when themissing information is available. Therefore, upon the reception of the“ACK” in case (2) of FIG. 12, the wireless device 130 may need to resetthe CW. Afterwards, before initiating a new CAT4 LBT, the wirelessdevice 130 shall adjust the CW in response of reception of explicit NACKfeedback (or presumed NACK) for the reference subframe (k+3).

The reception of the “NACK” in case (3) of FIG. 12, confirms that thedecision to double the CW upon T1 expiry was correct, therefore the CWis not reset. Afterwards, before initiating a new CAT4 LBT, the wirelessdevice 130 doubles the CW from 2*CW to 4*CW in response of NACKcorresponding to the reference subframe k+3.

Example 2 in the second group of examples: If the wireless device 130increases the contention to the next higher value due to timer expiryand receives a positive feedback corresponding to the HARQ ID linked thelatest expired timer, the wireless device 130 may reset the CW.

Third Group of Examples: Multiple Timer Expire+Late Feedback

This section is an extension of the previous section. The assumption inthe above examples is that in:

-   -   Case 1 of FIG. 13: subframe “k” Acked, subframe “k+3” Nacked    -   Case 2 of FIG. 13: subframe “k” Nacked, subframe “k+3” Acked.

The same rule applies as in the case of single timer expiry. Thefeedback corresponding to the latest expired timer is what reflects thechannel situation. That is, the reference subframe is the subframecorresponding to the HARQ ID linked the latest expired timer. Therefore,in case 1 of FIG. 13, the CW is unchanged since k+3 is Nacked, while incase 2 of FIG. 13, the wireless device 130 resets the CW beforeinitializing a new sensing procedure such as CAT4 LBT.

As another example in the third group of examples: The feedbackcorresponding to all the expired timers are taken in consideration.There will be multiple reference subframes each corresponding to a HARQid of an expired timer. As non-limiting examples, the CW is reset if:

-   -   if all reference subframes are Acked    -   if latest reference subframe is Acked    -   if more than X % of the reference subframes are Acked    -   if less than Y % of the reference subframes are Nacked

Certain embodiments disclosed herein may provide one or more of thefollowing technical advantage(s), which may be summarized as that theyprovide for methods for contention window adjustment for autonomous ULoperation, specifically when there is no feedback for previous Category4 LBT UL transmissions. The methods define the first communication node101 behavior that ensures:

-   -   efficient and optimized adjustment of the CW;    -   avoid unnecessary increase of CW.

FIG. 14 depicts two different examples, respectively, of the arrangementthat the first communication node 101 may comprise. In some embodiments,the first communication node 101 may comprise the following arrangementdepicted in FIG. 14 top.

The embodiments herein in the first communication node 101 may beimplemented through one or more processors, such as a processor 1407 inthe first communication node 101 depicted in FIG. 14, together withcomputer program code for performing the functions and actions of theembodiments herein. A processor, as used herein, may be understood to bea hardware component. The program code mentioned above may also beprovided as a computer program product, for instance in the form of adata carrier carrying computer program code for performing theembodiments herein when being loaded into the first communication node101. One such carrier may be in the form of a CD ROM disc. It is howeverfeasible with other data carriers such as a memory stick. The computerprogram code may furthermore be provided as pure program code on aserver and downloaded to the first communication node 101.

The first communication node 101 may further comprise a memory 1408comprising one or more memory units. The memory 1408 is arranged to beused to store obtained information, store data, configurations,schedulings, and applications etc. to perform the methods herein whenbeing executed in the first communication node 101.

In some embodiments, the first communication node 101 may receiveinformation from, e.g., the second communication node 102, through areceiving port 1409. In some embodiments, the receiving port 1409 maybe, for example, connected to one or more antennas in firstcommunication node 101. In other embodiments, the first communicationnode 101 may receive information from another structure in the wirelesscommunications network 100 through the receiving port 1409. Since thereceiving port 1409 may be in communication with the processor 1407, thereceiving port 1409 may then send the received information to theprocessor 1407. The receiving port 1409 may also be configured toreceive other information.

The processor 1407 in the first communication node 101 may be furtherconfigured to transmit or send information to e.g., the secondcommunication node 102, another structure in the wireless communicationsnetwork 100, through a sending port 1410, which may be in communicationwith the processor 1407, and the memory 1408.

Those skilled in the art will also appreciate that the providing unit1401, the initiating unit 1402, the receiving unit 1403, the refrainingunit 1404, the resetting unit 1405, and the other units 1406 describedabove may refer to a combination of analog and digital circuits, and/orone or more processors configured with software and/or firmware, e.g.,stored in memory, that, when executed by the one or more processors suchas the processor 1407, perform as described above. One or more of theseprocessors, as well as the other digital hardware, may be included in asingle Application-Specific Integrated Circuit (ASIC), or severalprocessors and various digital hardware may be distributed among severalseparate components, whether individually packaged or assembled into aSystem-on-a-Chip (SoC).

Also, in some embodiments, the different units 1401-1405 described abovemay be implemented as one or more applications running on one or moreprocessors such as the processor 1407.

Thus, the methods according to the embodiments described herein for thefirst communication node 101 may be respectively implemented by means ofa computer program 1411 product, comprising instructions, i.e., softwarecode portions, which, when executed on at least one processor 1407,cause the at least one processor 1407 to carry out the actions describedherein, as performed by the first communication node 101. The computerprogram 1411 product may be stored on a computer-readable storage medium1412. The computer-readable storage medium 1412, having stored thereonthe computer program 1411, may comprise instructions which, whenexecuted on at least one processor 1407, cause the at least oneprocessor 1407 to carry out the actions described herein, as performedby the first communication node 101. In some embodiments, thecomputer-readable storage medium 1412 may be a non-transitorycomputer-readable storage medium, such as a CD ROM disc, or a memorystick. In other embodiments, the computer program 1411 product may bestored on a carrier containing the computer program 1411 just described,wherein the carrier is one of an electronic signal, optical signal,radio signal, or the computer-readable storage medium 1412, as describedabove.

The first communication node 101 may comprise a communication interfaceconfigured to facilitate communications between the first communicationnode 101 and other nodes or devices, e.g., the second communication node102. The interface may, for example, include a transceiver configured totransmit and receive radio signals over an air interface in accordancewith a suitable standard.

In other embodiments, the first communication node 101 may comprise thefollowing arrangement depicted in FIG. 14 low. The first communicationnode 101 may comprise a processing circuitry 1407, e.g., one or moreprocessors such as the processor 1407, in the first communication node101 and the memory 1408. The first communication node 101 may alsocomprise a radio circuitry 1413, which may comprise e.g., the receivingport 1409 and the sending port 1410. The processing circuitry 1407 maybe configured to, or operable to, perform the method actions accordingto FIG. 10, and/or FIGS. 33-37, in a similar manner as that described inrelation to FIG. 14 top. The radio circuitry 1413 may be configured toset up and maintain at least a wireless connection with the firstcommunication node 101. Circuitry may be understood herein as a hardwarecomponent.

Hence, embodiments herein also relate to the first communication node101 operative to operate in the wireless communications network 100. Thefirst communication node 101 may comprise the processing circuitry 1407and the memory 1408, said memory 1408 containing instructions executableby said processing circuitry 1407, whereby the first communication node101 is further operative to perform the actions described herein inrelation to the first communication node 101, e.g., in FIG. 10, and/orFIG. 15-20.

Further Extensions and Variations

FIG. 15: Telecommunication network connected via an intermediate networkto a host computer in accordance with some embodiments

With reference to FIG. 15, in accordance with an embodiment, acommunication system includes telecommunication network 3210 such as thewireless communications network 100, for example, a 3GPP-type cellularnetwork, which comprises access network 3211, such as a radio accessnetwork, and core network 3214. Access network 3211 comprises aplurality of network nodes such as the second communication node 102.For example, base stations 3212 a, 3212 b, 3212 c, such as NBs, eNBs,gNBs or other types of wireless access points, each defining acorresponding coverage area 3213 a, 3213 b, 3213 c. Each base station3212 a, 3212 b, 3212 c is connectable to core network 3214 over a wiredor wireless connection 3215. In FIG. 15, a first UE 3291 located incoverage area 3213 c is configured to wirelessly connect to, or be pagedby, the corresponding base station 3212 c. A second UE 3292 in coveragearea 3213 a is wirelessly connectable to the corresponding base station3212 a. While a plurality of UEs 3291, 3292 are illustrated in thisexample, the disclosed embodiments are equally applicable to a situationwhere a sole UE is in the coverage area or where a sole UE is connectingto the corresponding base station 3212. Any of the UEs 3291, 3292 may beconsidered examples of the first communication node 101.

Telecommunication network 3210 is itself connected to host computer3230, which may be embodied in the hardware and/or software of astandalone server, a cloud-implemented server, a distributed server oras processing resources in a server farm. Host computer 3230 may beunder the ownership or control of a service provider, or may be operatedby the service provider or on behalf of the service provider.Connections 3221 and 3222 between telecommunication network 3210 andhost computer 3230 may extend directly from core network 3214 to hostcomputer 3230 or may go via an optional intermediate network 3220.Intermediate network 3220 may be one of, or a combination of more thanone of, a public, private or hosted network; intermediate network 3220,if any, may be a backbone network or the Internet; in particular,intermediate network 3220 may comprise two or more sub-networks (notshown).

The communication system of FIG. 15 as a whole enables connectivitybetween the connected UEs 3291, 3292 and host computer 3230. Theconnectivity may be described as an over-the-top (OTT) connection 3250.Host computer 3230 and the connected UEs 3291, 3292 are configured tocommunicate data and/or signaling via OTT connection 3250, using accessnetwork 3211, core network 3214, any intermediate network 3220 andpossible further infrastructure (not shown) as intermediaries. OTTconnection 3250 may be transparent in the sense that the participatingcommunication devices through which OTT connection 3250 passes areunaware of routing of uplink and downlink communications. For example,base station 3212 may not or need not be informed about the past routingof an incoming downlink communication with data originating from hostcomputer 3230 to be forwarded (e.g., handed over) to a connected UE3291. Similarly, base station 3212 need not be aware of the futurerouting of an outgoing uplink communication originating from the UE 3291towards the host computer 3230.

In relation to FIGS. 16, 17, 18, 19, and 20, which are described next,it may be understood that a UE is an example of the first communicationnode 101, and that any description provided for the UE equally appliesto the first communication node 101. It may be also understood that thebase station may be considered an example of the second communicationnode 102, and that any description provided for the base station equallyapplies to the second communication node 102.

FIG. 16: Host computer communicating via a base station with a userequipment over a partially wireless connection in accordance with someembodiments

Example implementations, in accordance with an embodiment, of the firstcommunication node 101, e.g., a UE, and the second communication node102, e.g., a base station and host computer discussed in the precedingparagraphs will now be described with reference to FIG. 16. Incommunication system 3300, such as the wireless communications network100, host computer 3310 comprises hardware 3315 including communicationinterface 3316 configured to set up and maintain a wired or wirelessconnection with an interface of a different communication device ofcommunication system 3300. Host computer 3310 further comprisesprocessing circuitry 3318, which may have storage and/or processingcapabilities. In particular, processing circuitry 3318 may comprise oneor more programmable processors, application-specific integratedcircuits, field programmable gate arrays or combinations of these (notshown) adapted to execute instructions. Host computer 3310 furthercomprises software 3311, which is stored in or accessible by hostcomputer 3310 and executable by processing circuitry 3318. Software 3311includes host application 3312. Host application 3312 may be operable toprovide a service to a remote user, such as UE 3330 connecting via OTTconnection 3350 terminating at UE 3330 and host computer 3310. Inproviding the service to the remote user, host application 3312 mayprovide user data which is transmitted using OTT connection 3350.

Communication system 3300 further includes the second communication node102, exemplified in FIG. 16 as a base station 3320 provided in atelecommunication system and comprising hardware 3325 enabling it tocommunicate with host computer 3310 and with UE 3330. Hardware 3325 mayinclude communication interface 3326 for setting up and maintaining awired or wireless connection with an interface of a differentcommunication device of communication system 3300, as well as radiointerface 3327 for setting up and maintaining at least wirelessconnection 3370 with the first communication node 101, exemplified inFIG. 16 as a UE 3330 located in a coverage area (not shown in FIG. 16)served by base station 3320. Communication interface 3326 may beconfigured to facilitate connection 3360 to host computer 3310.Connection 3360 may be direct or it may pass through a core network (notshown in FIG. 16) of the telecommunication system and/or through one ormore intermediate networks outside the telecommunication system. In theembodiment shown, hardware 3325 of base station 3320 further includesprocessing circuitry 3328, which may comprise one or more programmableprocessors, application-specific integrated circuits, field programmablegate arrays or combinations of these (not shown) adapted to executeinstructions. Base station 3320 further has software 3321 storedinternally or accessible via an external connection.

Communication system 3300 further includes UE 3330 already referred to.Its hardware 3335 may include radio interface 3337 configured to set upand maintain wireless connection 3370 with a base station serving acoverage area in which UE 3330 is currently located. Hardware 3335 of UE3330 further includes processing circuitry 3338, which may comprise oneor more programmable processors, application-specific integratedcircuits, field programmable gate arrays or combinations of these (notshown) adapted to execute instructions. UE 3330 further comprisessoftware 3331, which is stored in or accessible by UE 3330 andexecutable by processing circuitry 3338. Software 3331 includes clientapplication 3332. Client application 3332 may be operable to provide aservice to a human or non-human user via UE 3330, with the support ofhost computer 3310. In host computer 3310, an executing host application3312 may communicate with the executing client application 3332 via OTTconnection 3350 terminating at UE 3330 and host computer 3310. Inproviding the service to the user, client application 3332 may receiverequest data from host application 3312 and provide user data inresponse to the request data. OTT connection 3350 may transfer both therequest data and the user data. Client application 3332 may interactwith the user to generate the user data that it provides.

It is noted that host computer 3310, base station 3320 and UE 3330illustrated in FIG. 16 may be similar or identical to host computer3230, one of base stations 3212 a, 3212 b, 3212 c and one of UEs 3291,3292 of FIG. 15, respectively. This is to say, the inner workings ofthese entities may be as shown in FIG. 16 and independently, thesurrounding network topology may be that of FIG. 15.

In FIG. 16, OTT connection 3350 has been drawn abstractly to illustratethe communication between host computer 3310 and UE 3330 via basestation 3320, without explicit reference to any intermediary devices andthe precise routing of messages via these devices. Networkinfrastructure may determine the routing, which it may be configured tohide from UE 3330 or from the service provider operating host computer3310, or both. While OTT connection 3350 is active, the networkinfrastructure may further take decisions by which it dynamicallychanges the routing (e.g., on the basis of load balancing considerationor reconfiguration of the network).

Wireless connection 3370 between UE 3330 and base station 3320 is inaccordance with the teachings of the embodiments described throughoutthis disclosure. One or more of the various embodiments improve theperformance of OTT services provided to UE 3330 using OTT connection3350, in which wireless connection 3370 forms the last segment. Moreprecisely, the teachings of these embodiments may improve the spectrumefficiency when accessing the channel, and reduce latency, and therebyprovide benefits such as reduced user waiting time, betterresponsiveness and extended battery lifetime.

A measurement procedure may be provided for the purpose of monitoringdata rate, latency and other factors on which the one or moreembodiments improve. There may further be an optional networkfunctionality for reconfiguring OTT connection 3350 between hostcomputer 3310 and UE 3330, in response to variations in the measurementresults. The measurement procedure and/or the network functionality forreconfiguring OTT connection 3350 may be implemented in software 3311and hardware 3315 of host computer 3310 or in software 3331 and hardware3335 of UE 3330, or both. In embodiments, sensors (not shown) may bedeployed in or in association with communication devices through whichOTT connection 3350 passes; the sensors may participate in themeasurement procedure by supplying values of the monitored quantitiesexemplified above, or supplying values of other physical quantities fromwhich software 3311, 3331 may compute or estimate the monitoredquantities. The reconfiguring of OTT connection 3350 may include messageformat, retransmission settings, preferred routing etc.; thereconfiguring need not affect base station 3320, and it may be unknownor imperceptible to base station 3320. Such procedures andfunctionalities may be known and practiced in the art. In certainembodiments, measurements may involve proprietary UE signalingfacilitating host computer 3310's measurements of throughput,propagation times, latency and the like. The measurements may beimplemented in that software 3311 and 3331 causes messages to betransmitted, in particular empty or ‘dummy’ messages, using OTTconnection 3350 while it monitors propagation times, errors etc.

FIG. 17: Methods implemented in a communication system including a hostcomputer, a base station and a user equipment in accordance with someembodiments

FIG. 17 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 15 and 16. Forsimplicity of the present disclosure, only drawing references to FIG. 17will be included in this section. In step 3410, the host computerprovides user data. In substep 3411 (which may be optional) of step3410, the host computer provides the user data by executing a hostapplication. In step 3420, the host computer initiates a transmissioncarrying the user data to the UE. In step 3430 (which may be optional),the base station transmits to the UE the user data which was carried inthe transmission that the host computer initiated, in accordance withthe teachings of the embodiments described throughout this disclosure.In step 3440 (which may also be optional), the UE executes a clientapplication associated with the host application executed by the hostcomputer.

FIG. 18: Methods implemented in a communication system including a hostcomputer, a base station and a user equipment in accordance with someembodiments

FIG. 18 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 15 and 16. Forsimplicity of the present disclosure, only drawing references to FIG. 18will be included in this section. In step 3510 of the method, the hostcomputer provides user data. In an optional substep (not shown) the hostcomputer provides the user data by executing a host application. In step3520, the host computer initiates a transmission carrying the user datato the UE. The transmission may pass via the base station, in accordancewith the teachings of the embodiments described throughout thisdisclosure. In step 3530 (which may be optional), the UE receives theuser data carried in the transmission.

FIG. 19: Methods implemented in a communication system including a hostcomputer, a base station and a user equipment in accordance with someembodiments

FIG. 19 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 15 and 16. Forsimplicity of the present disclosure, only drawing references to FIG. 19will be included in this section. In step 3610 (which may be optional),the UE receives input data provided by the host computer. Additionallyor alternatively, in step 3620, the UE provides user data. In substep3621 (which may be optional) of step 3620, the UE provides the user databy executing a client application. In substep 3611 (which may beoptional) of step 3610, the UE executes a client application whichprovides the user data in reaction to the received input data providedby the host computer. In providing the user data, the executed clientapplication may further consider user input received from the user.Regardless of the specific manner in which the user data was provided,the UE initiates, in substep 3630 (which may be optional), transmissionof the user data to the host computer. In step 3640 of the method, thehost computer receives the user data transmitted from the UE, inaccordance with the teachings of the embodiments described throughoutthis disclosure.

FIG. 20: Methods implemented in a communication system including a hostcomputer, a base station and a user equipment in accordance with someembodiments

FIG. 20 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 15 and 16. Forsimplicity of the present disclosure, only drawing references to FIG. 20will be included in this section. In step 3710 (which may be optional),in accordance with the teachings of the embodiments described throughoutthis disclosure, the base station receives user data from the UE. Instep 3720 (which may be optional), the base station initiatestransmission of the received user data to the host computer. In step3730 (which may be optional), the host computer receives the user datacarried in the transmission initiated by the base station.

Any appropriate steps, methods, features, functions, or benefitsdisclosed herein may be performed through one or more functional unitsor modules of one or more virtual apparatuses. Each virtual apparatusmay comprise a number of these functional units. These functional unitsmay be implemented via processing circuitry, which may include one ormore microprocessor or microcontrollers, as well as other digitalhardware, which may include digital signal processors (DSPs),special-purpose digital logic, and the like. The processing circuitrymay be configured to execute program code stored in memory, which mayinclude one or several types of memory such as read-only memory (ROM),random-access memory (RAM), cache memory, flash memory devices, opticalstorage devices, etc. Program code stored in memory includes programinstructions for executing one or more telecommunications and/or datacommunications protocols as well as instructions for carrying out one ormore of the techniques described herein. In some implementations, theprocessing circuitry may be used to cause the respective functional unitto perform corresponding functions according one or more embodiments ofthe present disclosure.

The term unit may have conventional meaning in the field of electronics,electrical devices and/or electronic devices and may include, forexample, electrical and/or electronic circuitry, devices, modules,processors, memories, logic solid state and/or discrete devices,computer programs or instructions for carrying out respective tasks,procedures, computations, outputs, and/or displaying functions, and soon, as such as those that are described herein.

Further Numbered Embodiments

21. A user equipment (UE) configured to communicate with a base station,the UE comprising a radio interface and processing circuitry configuredto perform one or more of the actions described herein as performed bythe first communication node 101.25. A communication system including a host computer comprising:

processing circuitry configured to provide user data; and

a communication interface configured to forward user data to a cellularnetwork for transmission to a user equipment (UE),

wherein the UE comprises a radio interface and processing circuitry, theUE's processing circuitry configured to perform one or more of theactions described herein as performed by the first communication node101.

26. The communication system of embodiment 25, further including the UE.27. The communication system of embodiment 26, wherein the cellularnetwork further includes a base station configured to communicate withthe UE.28. The communication system of embodiment 26 or 27, wherein:

the processing circuitry of the host computer is configured to execute ahost application, thereby providing the user data; and

the UE's processing circuitry is configured to execute a clientapplication associated with the host application.

31. A method implemented in a user equipment (UE), comprising one ormore of the actions described herein as performed by the firstcommunication node 101.35. A method implemented in a communication system including a hostcomputer, a base station and a user equipment (UE), the methodcomprising:

at the host computer, providing user data; and

at the host computer, initiating a transmission carrying the user datato the UE via a cellular network comprising the base station, whereinthe UE performs one or more of the actions described herein as performedby the first communication node 101.

36. The method of embodiment 35, further comprising:

at the UE, receiving the user data from the base station.

41. A user equipment (UE) configured to communicate with a base station,the UE comprising a radio interface and processing circuitry configuredto perform one or more of the actions described herein as performed bythe first communication node 101.45. A communication system including a host computer comprising:

a communication interface configured to receive user data originatingfrom a transmission from a user equipment (UE) to a base station,

wherein the UE comprises a radio interface and processing circuitry, theUE's processing circuitry configured to: perform one or more of theactions described herein as performed by the first communication node101.

46. The communication system of embodiment 45, further including the UE.47. The communication system of embodiment 46, further including thebase station, wherein the base station comprises a radio interfaceconfigured to communicate with the UE and a communication interfaceconfigured to forward to the host computer the user data carried by atransmission from the UE to the base station.48. The communication system of embodiment 46 or 47, wherein:

the processing circuitry of the host computer is configured to execute ahost application; and

the UE's processing circuitry is configured to execute a clientapplication associated with the host application, thereby providing theuser data.

49. The communication system of embodiment 46 or 47, wherein:

the processing circuitry of the host computer is configured to execute ahost application, thereby providing request data; and

the UE's processing circuitry is configured to execute a clientapplication associated with the host application, thereby providing theuser data in response to the request data.

51. A method implemented in a user equipment (UE), comprising one ormore of the actions described herein as performed by the firstcommunication node 101.52. The method of embodiment 51, further comprising:

providing user data; and

forwarding the user data to a host computer via the transmission to thebase station.

55. A method implemented in a communication system including a hostcomputer, a base station and a user equipment (UE), the methodcomprising:

at the host computer, receiving user data transmitted to the basestation from the UE, wherein the UE performs one or more of the actionsdescribed herein as performed by the first communication node 101.

56. The method of embodiment 55, further comprising:

at the UE, providing the user data to the base station.

57. The method of embodiment 56, further comprising:

at the UE, executing a client application, thereby providing the userdata to be transmitted; and

at the host computer, executing a host application associated with theclient application.

58. The method of embodiment 56, further comprising:

at the UE, executing a client application; and

at the UE, receiving input data to the client application, the inputdata being provided at the host computer by executing a host applicationassociated with the client application,

wherein the user data to be transmitted is provided by the clientapplication in response to the input data.

75. A method implemented in a communication system including a hostcomputer, a base station and a user equipment (UE), the methodcomprising:

at the host computer, receiving, from the base station, user dataoriginating from a transmission which the base station has received fromthe UE, wherein the UE performs one or more of the actions describedherein as performed by the first communication node 101.

76. The method of embodiment 75, further comprising:

at the base station, receiving the user data from the UE.

77. The method of embodiment 76, further comprising:

at the base station, initiating a transmission of the received user datato the host computer.

ABBREVIATIONS

At least some of the following abbreviations may be used in thisdisclosure. If there is an inconsistency between abbreviations,preference should be given to how it is used above. If listed multipletimes below, the first listing should be preferred over any subsequentlisting(s).

-   3GPP 3rd Generation Partnership Project-   5G 5th Generation-   DL Downlink-   eNB E-UTRAN NodeB-   E-UTRA Evolved UTRA-   E-UTRAN Evolved UTRAN-   GERAN GSM EDGE Radio Access Network-   gNB Base station in NR-   GSM Global System for Mobile communication-   HSPA High Speed Packet Access-   LTE Long-Term Evolution-   OFDM Orthogonal Frequency Division Multiplexing-   UE User Equipment-   UL Uplink-   UMTS Universal Mobile Telecommunication System-   UTRA Universal Terrestrial Radio Access-   UTRAN Universal Terrestrial Radio Access Network-   WCDMA Wide CDMA-   WLAN Wide Local Area Network-   BSR Buffer Status Request-   CC Component Carrier-   CCA Clear Channel Assessment-   CQI Channel Quality Information-   CRC Cyclic Redundancy Check-   DCI Downlink Control Information-   DL Downlink-   DMTC DRS Measurement Timing Configuration-   DRS Discovery Reference Signal-   eNB evolved NodeB, base station-   UE User Equipment-   UL Uplink-   LAA Licensed-Assisted Access-   SCell Secondary Cell-   STA Station-   LBT Listen-before-talk-   LTE-U LTE in Unlicensed Spectrum-   PDCCH Physical Downlink Control Channel-   PMI Precoding Matrix Indicator-   PUSCH Physical Uplink Shared Channel-   RAT Radio Access Technology-   RNTI Radio Network Temporary Identifier-   TXOP Transmission Opportunity-   UL Uplink

REFERENCES

-   3GPP TS 36.211, V12.3.0 (2014-09), 3rd Generation Partnership    Project; Technical Specification Group Radio Access Network; Evolved    Universal Terrestrial Radio Access (E-UTRA); Physical Channels and    Modulation, Release 12-   3GPP TS 36.213, V12.3.0 (2014-09), 3rd Generation Partnership    Project; Technical Specification Group Radio Access Network; Evolved    Universal Terrestrial Radio Access (E-UTRA); Physical layer    procedures, Release 12-   3GPP TS 36.212, V12.6.0 (2015-03), 3rd Generation Partnership    Project; Technical Specification Group Radio Access Network; Evolved    Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control    (RRC), Release 12-   3GPP TS 36.321, V12.1.0 (2014-03), 3rd Generation Partnership    Project; Technical Specification Group Radio Access Network; Evolved    Universal Terrestrial Radio Access (E-UTRA); Medium Access Control    (MAC) protocol specification, Release 12

1. A method, performed by a first communication node operating in awireless communications network, the method comprising: adjusting avalue of a Contention Window, CW, from a first value to a second value,the second value being a higher value than the first value, adjustingthe value being based on: at least one feedback timer having expired ata time of performing a sensing procedure in the absence of one of: a) areceived uplink, UL, grant from a second communication node, and b) adownlink feedback from the second communication node for an AutonomousUplink, AUL, transmission from the first communication node; andfollowing adjusting the value: initiating a sensing procedure performedprior to a transmission of an UL burst to the second communication node,the sensing procedure using the adjusted value of the CW.
 2. The methodaccording to claim 1, wherein the value of the CW is adjusted for allpriority classes at the first communication node.
 3. The methodaccording to claim 1, wherein at the time of performing the sensingprocedure, the at least one feedback timer has expired in the absence ofany downlink transmission from the second communication node, andwherein the higher value is increased once to a next higher value. 4.The method according to claim 1, wherein at the time of performing thesensing procedure, the at least one feedback timer has expired, and atleast one downlink, DL, transmission has been received from the secondcommunication node, the DL transmission being devoid of feedbackinformation, and wherein the higher value is increased to a next highervalue, wherein the next higher value is dependent on number of expiredfeedback timers.
 5. The method according to claim 1, wherein after thetime of performing the sensing procedure and the at least one feedbacktimer has expired, the method further comprises: receiving at least onedownlink, DL, transmission from the second communication node comprisingfeedback information, the feedback information being negative for alatest expired timer, and with the proviso that the feedback informationis negative, using a CW of the second value in a following sensingprocedure.
 6. The method according to claim 1, wherein after the time ofperforming the sensing procedure and the at least one feedback timer hasexpired, the method further comprises: receiving at least one downlink,DL, transmission from the second communication node comprising feedbackinformation, the feedback information being positive for a latestexpired timer, and with the proviso that the feedback information ispositive, resetting the value of the CW, from the second value to one ofthe first and a third value.
 7. The method according to claim 6, whereinthe feedback information is positive when at least one of the followingis fulfilled: a. all reference subframes are Acknowledged, Acked; b. alatest reference subframe is Acked; c. more than a set number ofreference subframes are Acked; d. less than a set number of thereference subframes are Negatively Acknowledged, Nacked; wherein thereference subframes correspond to subframes wherein the at least onefeedback timer was initiated.
 8. The method according to claim 5,wherein the received at least one DL transmission is associated with aHARQ Identifier, ID, linked to the latest expired timer.
 9. The methodaccording to claim 1, wherein each of the feedback timers corresponds toa respective Hybrid Automatic Repeat reQuest, HARQ, processcorresponding to a respective UL burst previously transmitted by thefirst communication node to the second communication node.
 10. A firstcommunication node configured to operate in a wireless communicationsnetwork, the first communication node being configured to: adjust avalue of a Contention Window, CW, from a first value to a second value,the second value being a higher value than the first value, adjustmentof the value being based on: at least one feedback timer having expiredat a time of performing a sensing procedure in the absence of one of: a)a received uplink, UL, grant from a second communication node, and b) adownlink feedback from the second communication node for an AutonomousUplink, AUL, transmission from the first communication node; andfollowing adjusting the value, configured to: initiate the sensingprocedure performed prior to a transmission of an UL burst to the secondcommunication node, the sensing procedure using the adjusted value ofthe CW.
 11. The first communication node according to claim 10, whereinthe value of the CW is adjusted for all priority classes at the firstcommunication node.
 12. The first communication node according to claim10, wherein at the time of performing the sensing procedure, the atleast one feedback timer has expired in the absence of any downlinktransmission from the second communication node, and wherein the highervalue is increased once to a next higher value.
 13. The firstcommunication node according to claim 10, wherein at the time ofperforming the sensing procedure, the at least one feedback timer hasexpired, and at least one downlink, DL, transmission has been receivedfrom the second communication node, the DL transmission being devoid offeedback information, and wherein the higher value is increased to anext higher value, wherein the next higher value is dependent on numberof expired feedback timers.
 14. The first communication node accordingto claim 10, wherein after the time of performing the sensing procedureand the at least one feedback timer has expired, the first communicationnode is further configured to: receive at least one downlink, DL,transmission from the second communication node comprising feedbackinformation, the feedback information being negative for a latestexpired timer, and with the proviso that the feedback information isnegative, use the CW of the second value in a following sensingprocedure.
 15. The first communication node according to claim 10,wherein after the time of performing the sensing procedure and the atleast one feedback timer has expired, the first communication node isfurther configured to: receive at least one downlink, DL, transmissionfrom the second communication node comprising feedback information, thefeedback information being positive for a latest expired timer, and withthe proviso that the feedback information is positive, reset the valueof the CW, from the second value to one of the first and a third value.16. The first communication node according to claim 15, wherein thefeedback information is positive when at least one of the following isfulfilled: a. all reference subframes are Acknowledged, Acked; b. alatest reference subframe is Acked; c. more than a set number ofreference subframes are Acked; d. less than a set number of thereference subframes are Negatively Acknowledged, Nacked; wherein thereference subframes correspond to subframes wherein the one or morefeedback timers were initiated.
 17. The first communication nodeaccording to claim 14, wherein the received at least one DL transmissionis associated with a HARQ Identifier, ID, linked to the latest expiredtimer.
 18. The first communication node according to claim 10, whereineach of the feedback timers corresponds to a respective Hybrid AutomaticRepeat reQuest, HARQ, process corresponding to a respective UL burstpreviously transmitted by the first communication node to the secondcommunication node.
 19. (canceled)
 20. A computer-readable storagemedium, having stored thereon a computer program product comprisinginstructions which, when executed on at least one processor, cause theat least one processor to carry out a method performed by a firstcommunication node operating in a wireless communications network, themethod comprising: adjusting a value of a Contention Window, CW, from afirst value to a second value, the second value being a higher valuethan the first value, adjusting the value being based on: at least onefeedback timer having expired at a time of performing a sensingprocedure in the absence of one of: a) a received uplink, UL, grant froma second communication node, and b) a downlink feedback from the secondcommunication node for an Autonomous Uplink, AUL, transmission from thefirst communication node; and following adjusting the value: initiatinga sensing procedure performed prior to a transmission of an UL burst tothe second communication node, the sensing procedure using the adjustedvalue of the CW.
 21. The method according to claim 2, wherein at thetime of performing the sensing procedure, the at least one feedbacktimer has expired in the absence of any downlink transmission from thesecond communication node, and wherein the higher value is increasedonce to a next higher value.